Diaphragm pacers as a treatment for congenital central hypoventilation syndrome.

Congenital central hypoventilation syndrome is a rare syndrome present from birth, and is defined as the failure of automatic control of breathing. All patients with congenital central hypoventilation syndrome require life-long ventilatory support during sleep, although approximately a third of patients require ventilatory support 24 h per day. Diaphragm pacers offer a modality of ventilatory support that affords congenital central hypoventilation syndrome patients with maximal mobility for full-time ventilatory patients, and they may allow for a more normal lifestyle in the appropriate patient. They may permit tracheostomy decannulation in those requiring only support during sleep. Diaphragm pacing entails surgical placement of an electrode onto the phrenic nerve, connected to a subcutaneous receiver. There is an external battery-operated transmitter and antenna placed on the skin over the receiver. The transmitter emits energy, similar to radio transmission, which is converted into an electrical current by the receiver. This stimulates the phrenic nerve resulting in a diaphragmatic contraction. Settings on the transmitter include respiratory rate and electrical voltage, and are adjusted to give enough tidal volume to allow for adequate oxygenation and ventilation. Therefore, diaphragm pacing is an attractive alternative mode of mechanically assisted ventilation for many patients with congenital central hypoventilation syndrome.